This invention relates to an electrode unit for integrally forming the conductors of an electric wire into a terminal, and relates to a terminal-formed electric wire.
FIG. 7 is a perspective view of a conventional keyhole-shaped terminal 19 and an electric wire 20 connected therewith. A procedure of connecting the terminal 19 and the wire 20 with each other is now described with reference to FIGS. 8(A), 8(B) and 8(C). The conductors 22 of the electric wire 20 are first set inside a pair of calked parts 21 provided on the straight portion of the terminal 19. The calked parts 21 are then pressed by an anvil 24 having a curved top 23, and a crimper 26 having two grooves 25, so that the calked parts are shaped in conformity with the forms of the grooves. The calked parts 21 are thus curved inward more into pressure contact with the conductors 22 of the wire 20 so that the terminal and the wire are electrically and mechanically coupled with each other.
However, if the conductors 22 are made of a metal different from that for the calked parts 21 or there are oxide films on the conductors or the calked parts, the electric contact resistance between them is so high that an electricity loss is caused or/and the electric coupling lacks long-period stability. This is a problem.
To solve the above-mentioned problem, electric wires 27 integrally formed with a terminal 28 as shown in FIG. 9 were proposed by the present applicant in Japanese Unexamined Utility Model Application No. 77880/87. The conductors 29 of the electric wires 27 are bundled and formed together at one end of each of them to constitute the terminal 28. However, it is difficult to form the numerous thin conductors 29 together solidly into the terminal 28. This is a problem. Therefore, a means for easily and surely forming an electric wire with a terminal has been desired.